Dental restoration structures are known as illustrated by U.S. Pat. Nos. 5,199,873 to Schulte et al, and 4,932,868 to Linkow et al, and by Ledermann et al, Schweiz Monatsschr. Zahnmed., vol. 101 (5), pp. 611-617 (1991). In this respect, prior workers have made a considerable effort to provide an improved implant. Implant failure can lead to significant destruction of alveolar bone. It has been found through prior effort that self-tapping implants are advantageous. Also found to be beneficial are single body implants.
Commercial implants include the self-tapping, single body implant described in the Ledermann et al publication. This implant has a tapered profile and longitudinal grooves that form cutting teeth. An interior cavity includes a hexagonally-shaped, upper portion for receiving an abutment member having a longitudinal bore, and a lower portion for engaging threads of a screw for securing the abutment member to the implant. The abutment member is used to connect the implant to a crown structure.
However, pressure-induced bone resorption or necrosis may occur with the implant. Additionally, when the abutment member is secured to the implant by rotation of the abutment screw, undesirable additional cutting of bone or detachment may occur due to engagement of the implant cutting teeth.
A crown structure often used with the implant of the Ledermann et al publication, includes a transverse inclined bore for coaxial alignment with a corresponding transverse inclined bore of the abutment member. In this case, the crown structure is attached to a crown end of the abutment by means of a transverse screw threaded into the aligned bores. The bore in the crown structure may advantageously be slightly higher than the bore in the abutment to produce a press fit of the crown to the implant when the bores are aligned by use of the screw.
Commercial crown structures for use with implants are typically prepared from a block of gold of about 2 to 3 mm thickness. These crown structures are formed to have an appropriate interior shape by removal of gold from the gold block. The process is labor-intensive and costly.
Accordingly, there continues to be a need for improved dental implants and for less expensive dental crowns for use with implants. Likewise, there is a need for a process for making less expensive dental crowns for use with implants.